The trick that allows vim to do so, is to enable multiple line matching by using the special regular expression escape
'\_.'combined with a greedy qualifier.
The help line in the vim documentation offers how this trick is accomplished:
\_. Matches any single character or end-of-line.
Careful: "\_.*" matches all text to the end of the buffer!
It's precisely the warning highlighted in red that we are going to 'exploit' in order to allow multi-line matching to occur.
An example where this sort of matching usually applies are usually found in data formats like HTML/XML, where data sets can span multiple lines, separated by markups rather than newline characters.
As an example, say, if you wanted to match data that's bounded by
<div>markup pairs, you'll have the following regular expression:
I often use this technique as a 'quick and dirty' way of breaking up markups into separate data easily, especially if it's only for a one-off use that doesn't merit writing a Perl or Awk scripts.
If you like reading this, you may also enjoy: